# i読書 vs カクヨムViewer

The clearest difference is rating: カクヨムViewer at 4.7 against i読書's 3.0. カクヨムViewer also leads on in-app purchases (none vs 1) and update cadence (fortnightly vs every 2 months). i読書's advantage is review sentiment (50% vs 12%) and ads (none vs shown). On price and device support there is nothing between them.

Both are free to download. i読書 sells 1 one-off in-app purchase. カクヨムViewer asks for nothing beyond the download.

カクヨムViewer holds the better App Store score, 4.7 against 3.0. That said, the two scores are not equally well evidenced: カクヨムViewer has 49 ratings behind it against 3, so its average is the more settled of the two. Written reviews complicate that: 50% of i読書's written reviews are positive against 12% of カクヨムViewer's, so the app with the better star average is not the one people write more warmly about.

i読書 ships an update every 2 months, カクヨムViewer fortnightly. The most recent releases landed on October 8, 2026 and October 15, 2026 respectively.

## The numbers

| Metric | i読書 | カクヨムViewer |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [3.0 (3 ratings)](https://appshunter.io/ios/app/i/id534970999/reviews) | **[4.7 (49 ratings)](https://appshunter.io/ios/app/viewer-web/id1081762516/reviews)** |
| Number of ratings | 3 | **49** |
| Positive reviews | **50.0% of reviews** | 12.0% of reviews |
| In-app purchases | Yes | **No** |
| Ads | **No** | Yes |
| Update frequency | Every 2 months | **Fortnightly** |
| Monetization | **Free** | Free with in-app purchases |
| Size | 19 MB | 56 MB |
| Requires iOS | **7.0** | 18.6 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 4+ | 12+ |
| Developer | [yaslab](https://appshunter.io/developer/534971002) | [株式会社KADOKAWA](https://appshunter.io/developer/986639480) |

## What reviewers say

### i読書

[App page](https://appshunter.io/ios/app/i/id534970999)

This app allows users to download and read books from the Aozora Bunko library on their iPhone or iPad. Browse by author or title to find and save literary works for offline reading.

**Highlights:** Download Aozora Bunko books, Browse by author, Browse by title, Save books for offline reading, Simple interface

**Features:** Vision Pro support

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| 広告削除 | $0.99 | one-time |


### カクヨムViewer

[App page](https://appshunter.io/ios/app/viewer-web/id1081762516)

This app provides access to a vast collection of web novels and light novels, including original works and fanfiction. Users can customize their reading experience with adjustable backgrounds and fonts, and enjoy offline reading. It also offers a subscription service for exclusive new titles.

**Highlights:** Browse novels by genre, Follow favorite novels, Offline reading support, Customizable reader settings, Notifications for new chapters, Support original and fanfiction works

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases:** none


## Frequently asked questions

### Is i読書 free?

i読書 is free to download, with in-app purchases available.

### Is カクヨムViewer free?

カクヨムViewer is free to download, with no in-app purchases.

### Which has better reviews, i読書 or カクヨムViewer?

カクヨムViewer is rated higher. i読書 averages 3.0 out of 5 from 3 ratings, while カクヨムViewer averages 4.7 from 49 ratings.

### Do i読書 or カクヨムViewer have ads?

カクヨムViewer shows ads; i読書 does not.

### Which is updated more often, i読書 or カクヨムViewer?

i読書 ships an update every 2 months, and カクヨムViewer fortnightly. Most recently, i読書 was updated on October 8, 2026 and カクヨムViewer on October 15, 2026.

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*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*